January 9, 1866. ] 



JOURNAL OF HOBTICULTURE AND COTTAGE GARDENER. 



27 



garded aa of no value." Now, the agent which balances and 

 supports the mercurial column is the atmosphere. The earth 

 is surronnded by this atmosphere, weather is constantly chang- 

 ing, and with such changes atmospheric pressures increase and 

 diminish daily and hoiu'ly. That pressures do vary, and that 

 the barometer is affected by such variations, can bo demon- 

 strated in the followiug way : — Let any one take a portable 

 barometer to the summit of a hill, ha-ving, previously to start- 

 ing upwards, noted down the height at which the column stands. 

 Suppose the ascent to be 500 feet, it will be found that on ar- 

 riving at the summit the mercury has fallen considerably. Why 

 is this ? 'tt'hy should there be any change ? The reason is as 

 follows : In ascending the height a diminution in the density 

 of the atmosphere is experienced. The atmosphere which at 

 a lower heiglit supported the column of mercury will not sup- 

 port it at the top of the MU. The mercury falls. But let the 

 glass be brought down directly to the original starting point, and 

 the barometer will read once more at the same height as it did 

 at first. To those who are able to perform another experiment, 

 the atmospheric pressure on the column of mercnry is more 

 clearly and quickly illustrated. Place a skeleton syplion baro- 

 meter (simply the glass tube filled with mercury) under the re- 

 ceiver of an air-pump ; directly the pump is set in motion the 

 column will fall, and will continue so to do in proportion to 

 the rarefaction of the air. Now turn the stop-cock ; admit 

 fresh air in the place of that which has been pumped out ; 

 what is the result? The mercury returns to its original 

 height. 



I am perfectly persuaded of this, that if any one can firmly 

 fix upon his mind that atmospheric pressure is the cause which 

 regulates the osciUations of the barometer, and that during the 

 variations of the weather atmospheric pressures do vary, there 

 would then be more attention paid to the instrument, and per- 

 sons would try to fathom its movements and to investigate its 

 constant and sometimes apparently mysterious changes. In 

 all scientific researches, however, it must be remembered that 

 man is the being created. Let no one strive to dive into hid- 

 den mysteries simply and solely for the purpose of curiosity 

 and self-glorification, or for the piurpose of finding out what 

 has been wisely hid from man. On the contrary, let every one 

 so use his Imowledge as to enlarge and develope those gifts and 

 resources which have been placed at his command by an allwise 

 and bounteous Creator for his own enlightenment and that of 

 his fellow-creatures. — X., Surreij. 



THE FRUIT-BE.^RING AUCUBA J.VPONICA AS 



A DINNER-TABLE PLANT. 



Allow me to add this plant to the tastefully selected list 

 made by Mr. Hobson, for dinner-table decoration. In passing 

 through the Messrs. Osborns' nursery the other day, I noticed 

 some beautiful standard plants of the Aueuba loaded with its 

 bright red fruit, the berries being about the size of medium- 

 sized acorns, in bunches of from eight to sixteen. The plants 

 had nice symmetrical heads about 16 inches in diameter, and 

 clean stems from 18 to 24 inches in length, and half an inch 

 in diameter. Once seen, the fruiting Ancuba cannot fad to be 

 a favourite, and it is a valuable acquisition for decorative pur- 

 poses. I noticed, also, a number of standard Laurustinus of 

 the same dimensions as the Aucubas described, covered with 

 bloom and beautifully feathered down the stems, and which 

 cannot fail to be gems on the dinner-table. Now, if circular 

 pans made of zinc or of any other material were constructed to 

 fit over the mouths of the pots of such plants as described, and 

 these pans were planted with some of the Lycopods — such as 

 apodum, densum, or umbrosum, edged with cfesium or other 

 trailing Mosses to form a drapery over the edge, with a few 

 Crocuses or Snowdrops peeping through the green moss, the 

 whole would make a lovely ornament both above and below the 

 " line of vision " — quite a natural epergne. The pans should 

 be made in halves, with a circidar groove in the centre of each 

 for the stem of the plant, and have two clasps to secure the 

 entire pan.— P. M., Putney Heath. 



METEOROLOGY OF FRUIT-TEEE HOUSES. 



I HOPE Mr. Rivers will excuse the festivities of this season 

 having prevented me from replying sooner to his letter ; and I 

 may also add that now, when ever one is trying to feel so 



happy and saying .so many kind things to all the friends he 

 meets, I have no desire in this letter to appear personal. I 

 have often withstood the temptation to put in a smart thing, 

 and also crossed out what I was afraid might be taken for an 

 asperity ; but having strong opinions as to the advantages to 

 be gained by sun heat, gathered principally from my own 

 experiments, I thought I would try how they stood the test of 

 public opinion in your paper. Mr. Rivers answered me, and 

 I have been in this manner obliged to make the best defence 

 I could. 



A discussion on the merits of houses can hardly be kept from 

 wandering into questions of cultivation. Thus, Mr. Rivers seems 

 to think forced Peach trees should be treated in a diiferent way 

 from those gi'owu during the summer in an orchard-house. I 

 think it is time we had another name for this anti-season culti- 

 vation ; for with all the modem appliances it is no longer strictly 

 correct to speak of it as forcing a tree, thereby implying that 

 the tree is unfitted to carry a similar crop in the following year. 

 I have often heard gardeners say, " There is no use in this," 

 " I woiUd not go to the expense of that," and " You can grow 

 perfectly good crops without something else," — how much they 

 can dispense with, depending on the natural advantages of 

 their situation. The first step in aiding nature is the begin- 

 ning of forcing. When I first began growing fruit trees I was 

 not aware of the important difference between orchard-houses, 

 and thought an orchard-house was an orchard-house ; but now 

 I find it is, and it is not. Mr. Rivers tells me mine should 

 have answered, for they never fail with him. I reply I am 

 further north ; but he tells me this is no vahd reason, as his 

 climatic world reaches to Stornoway. He has not yet told me 

 what sort of a house this is. If it is a lean-to it is not 

 surprising, for a contemporary teUs us, " At Culloden House, 

 near Inverness, the middle-season Peaches, such as the 

 Noblesse, ripen perfectly almost every year in the open air." 

 Not a word about protection, and yet some must be used ; but 

 sheeting-up a wall at night is not counted. That a low night 

 temperatirre helps to ripen the fruit and wood, and consequently 

 the buds for the following year, I think I have tried what I 

 could to prove. It is the low night temperatures in spring 

 and simimer I want information upon, and if there is a suc- 

 cessful span-roofed orchard-house north of the midland counties 

 in which there is only a single row of four-inch pipes round 

 the house, and where ventilation is given as Mr. Rivers directs. 

 In the " Orchard-House," Mr. Rivers says he cannot ripen 

 November Peaches, but he can October. Should I, then, be 

 told in a poUte way that I mismanage mine if, by reason of my 

 climate being worse than his, I am obliged to resort to the 

 treatment he advises for these late Peaches ? At page 93, 

 rmder the head of " Clingstones," I find, " We shall by this 

 mode of culture imitate the warm autumnal nights of the 

 southern United States, and keep the fruit in a growing state 

 tUl the ripening period arrives. In a common orchard-house 

 without fire heat the cool nights in September seem to put the 

 trees at rest, and the very late Peaches, as I have experienced, 

 do not ripen well." After again reading this, the only con- 

 clusion I can come to is what I said in my second letter, which 

 provoked Mr. Rivers — that in the case of trees treated as mine 

 were, that is, exposed to a night temperature in July of 55°, 

 and in August of 45°, they will go to rest, notwithstanding a 

 high day temperature. 



Vines require a higher temperature than Peach trees to 

 enable them to perfect their fruit, and I think my letter in the 

 Journal of December 12th will not bear the construction Mr. 

 Rivers puts upon it. I certainly never intended to convey that 

 it was my opinion that Black Hambm-gh Grapes would ripen 

 better on an open wall than imder glass, much less was I 

 speaking of their relative chances against spring frosts. I will 

 repeat what I said : " Can any one tell me what advantage a 

 south wall has over a narrow span-roofed house, from having 

 taken its maxima and minima for a summer in a meteorologi- 

 cally favoured place ? I would rather have my Grapes or 

 Peaches, if I wished them to come in soon (early), resting 

 against such a wall, and enjoying its radiation all night long, 

 than be starved in an orchard-house with a temperature of 

 from 40° to 45°." Upon this Mr. Rivers proceeds to argue, but 

 I am not able to say if the figures he gives are the temperatures 

 of a south wall or of the open air ; however, as he takes up the 

 subject o seriously I am not imwilling to consider it also. 

 He gives .rom 100° to 120° as the maximum of a south wall in 

 May, and we are then to suppose that the air goes down to 26°. 

 How near will night radiation bring the temperature of the 

 wall to the atmospheric point ? I cannot answer the question. 



